RU2649825C1 - Device for transmission of biophysiological signals - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention relates to the field of medical technology and can be used to transmit electrical signals taken from the body of a biological object (human or animal) to a recording device. Device for transmitting biophysiological signals comprises a cable and a plurality of contacts connected with it. Cable includes a shell with a plurality of conductors disposed within it, and with a plurality of contacts are located on its outer side at a distance from each other and arranged to be placed on the body surface of the biological object. Each contact is electrically connected to the corresponding conductor. Common screen is placed between the shell and the conductors and located along the entire length of the conductors.

EFFECT: technical result consists in increasing reliability by reducing the level of interference in the transmitted signal.

5 cl, 5 dwg

Description

The present invention relates to the field of electrical engineering used in medicine, and can be used to transmit electrical signals taken from the body of a biological object (human or animal) to a recording device.

Known conductor ECG system [US 6891379 B2, "EKG WIRING SYSTEM", G01R 27/04, publ. May 10, 2005], in essence, a device for transmitting biophysiological signals, such as an electrocardiological signal, consisting of a cable and a connector for connecting to a recording device. The cable contains a sheath, inside of which are many coaxial conductors that are electrically connected to the connector. On the outer side of the shell at a distance from each other there are many contacts made with the possibility of placing on the surface of the body of a biological object. The contacts on the body are placed by connecting with electrodes that are attached directly to the skin. Each contact is electrically connected to a corresponding conductor.

This known device is selected as a prototype, since it has the largest number of essential features that match the essential features of the claimed invention. However, this prototype has a significant drawback, namely, low reliability due to the fact that electrical signals passing through coaxial conductors are susceptible to external interference. Sources of interference can be located both outside the cable and inside it. Examples of external sources of interference: static electrical discharges occurring in synthetic human underwear; household electrical appliances; medical equipment, especially electrosurgical equipment, etc. Internal sources of interference - mutual influence of currents of adjacent conductors; tribostatic interference arising from cable bends due to friction of the insulation of adjacent conductors. Since the level of biophysiological signals, such as an ECG, mainly lies in the range of ± 10 mV, external interference can be comparable with the signal and even exceed it several times. Interference distorts useful information and may make it wrong or impossible to isolate diagnostically significant signs. Internal interference is usually smaller, however, their removal is required in cases where there are special requirements for obtaining a high-quality clean signal.

The objective of the present invention is to provide a new device for transmitting biophysiological signals with the achievement of the following technical result: improving reliability by reducing the level of interference in the transmitted signal.

The problem is solved due to the fact that in the known device for transmitting biophysiological signals containing a cable and a plurality of contacts connected to it, the cable includes a sheath, inside which there are many conductors, and on its outer side there are many contacts made with the possibility of placing on the surface of the body of a biological object, each contact is electrically connected to a corresponding conductor, according to the present invention, a common screen is introduced N, interposed between the sheath and the conductors.

There are options for the development of the main technical solution, which consists in the fact that:

- each conductor is placed in an individual screen;

- individual screens are made of semiconductor material;

- overvoltage protection elements have been introduced, each of which is electrically located between the corresponding conductor and the common screen;

- overvoltage protection elements have been introduced, each of which is electrically located between the corresponding conductor and its individual screen.

Thus, using the totality of the claimed features, it is possible to increase the reliability of the device for transmitting biophysiological signals by introducing a common screen that provides protection from interference transmitted through coaxial conductors of electrical signals.

The essence of the claimed invention and the possibility of its practical implementation is illustrated by the description and drawings below.

In FIG. 1 shows a device for transmitting biophysiological signals, cable sections of which are made in the form of a “snake”.

In FIG. 2 shows a device for transmitting biophysiological signals, cable sections of which are made in the form of rings offset from each other.

In FIG. 3 shows a device for transmitting biophysiological signals, cable sections of which are made in the form of a spiral.

In FIG. 4 shows a cross section.

In FIG. 5 shows a device for transmitting biophysiological signals with a microcontroller unit.

The device (Fig. 1-5) for transmitting biophysiological signals comprises a cable 1 and a plurality of contacts 2 connected to it. Cable 1 includes a sheath 3, inside of which there are many conductors 4, and on its outer side at a distance from each other there are many contacts 2 made with the possibility of placement on the surface of the body of a biological object (not shown), each contact 2 is electrically connected to the corresponding conductor 4. The contacts on the body are placed by connecting with electrodes (not shown in the drawing), which are fixed directly to the skin.

A device for transmitting biophysiological signals can be connected to a recording device (not shown in the drawing) via cable 1 directly or using connector 5, to which cable 1 is electrically connected on one side.

In this case, the sections of cable 1 located between the contacts 2 are made elastically deformed and can be a “snake” (Fig. 1), many rings displaced from each other (Fig. 2) or spiral (Fig. 3). The magnitude of this elastic deformation of cable portions 1 is determined depending on the location parameters of the contacts on the body of the biological object (not shown in the drawing), namely, the distance between the points on the body on which contacts 2 should be fixed for correct removal and transmission of biophysiological signals. The length of the conductors 4 is made so that the necessary elastic deformation of the cable 1 does not lead to excessive tearing forces on the electrodes.

In the case where the sections of the cable 1 between the contacts (electrodes) 2 are made in the form of a “snake”, the manufacturing process includes laying the cable 1 in a shape that has grooves corresponding to the final shape of the “snake”, heating the cable 1, for example, using a hairdryer, to the state of thermoplasticity of the sheath, and the cooling of the cable 1. After cooling, the sections of the cable 1 retain the shape of a “snake”. The number of “snake” waves and their height in the area between the contacts 2 is determined by the diameter of the cable 1 and the nominal distance between the contacts 2. For example, for the cable section 1 with a diameter of 3 mm and the nominal distance between the contacts 2 30 cm, the number of snake waves can be 7-8 pcs ., the wave height of the snake can be 4-5 cm.

In the case where the sections of the cable 1 between the contacts (electrodes) 2 are made in the form of a flexible spiral, the manufacturing process of the spiral includes winding the cable 1 onto the rod with grooves, heating, for example, a hairdryer, to the state of thermoplasticity, cooling the cable 1, after which the sections of the cable 1 keep the shape of a spiral. The diameter of the spiral and the number of rings are selected depending on the diameter of the cable 1 and the nominal distance between the contacts 2. For example, for cable 1 with a diameter of 3 mm and the nominal distance between the contacts 2 30 cm, the diameter of the spiral can be 2 cm, the number of turns is 15 pcs.

In the case where the sections of the cable 1 between the contacts (electrodes) 2 are made in the form of one or more rings located approximately in the same plane parallel to each other with a shift, the manufacturing process is similar to the manufacture of a “snake”, and the shape has grooves in the form of rings. The diameter of the rings and their number are selected depending on the diameter of the cable 1 and the nominal distance between the contacts 2. For example, for the cable section 1 with a diameter of 3 mm and a nominal distance between the contacts of 30 cm, the diameter of the rings can be 5-8 cm, the number of rings is 1-3 pcs . Such “flat” rings less interfere with the patient under clothes and can be attached to the body at individual points with a patch.

Example

When moving, the human body changes its geometric dimensions. For example, when inhaling, the volume of the chest increases. On exhalation, it decreases. When performing various physical exercises, individual muscles become tense and, accordingly, thicken, while relaxing, they decrease in volume. Part of contacts 2 is established on the chest, which, when inhaling / exhaling, significantly changes linear dimensions. If the length of cable 1 between the contacts is exactly equal to the distance between the installation points on the body, then when these body sizes are changed, excessive voltage can lead to the breakdown of contacts 2, which can make a long (daily) recording defective. The cable 1, made in the form of a “snake”, allows the distance between the established contacts to be changed, and due to the elasticity of the “snake”, there are no strong forces at the contact attachment points. By decreasing the distance (for example, when exhaling), due to the springy properties, the “snake” reduces the length of the cable section 1, thereby preventing the cable 1 from sagging between the contacts 2 and the “bounce” of the signal resulting from this, which leads to an increase in the measurement accuracy.

Contacts 2 can be made in the form of electrodes for removing electrical potentials from the surface of the body of a biological object (not shown in the drawing) or in the form of contact attachment devices and electrical connections to electrodes for removing electrical potentials from the surface of the body of a biological object (not shown). The electrodes can be mounted on pneumatic suction cups (not shown in the drawing) or using a self-adhesive layer (not shown in the drawing). Contact fastening devices have a spring element (not shown in the drawing), which is worn on the metal part of the electrode.

Between the sheath 3 and the conductors 4 is placed a common screen 6, made, for example, of metal in the form of a woven mesh or spiral. The shield protects all conductors 4 from external interference.

Each conductor 4 can be placed in an individual shield 7 (Fig. 4). In this case, part or all of the screens 7 can be made of conductive plastic material, for example, carbon-containing polypropylene, carbon-containing polyethylene, carbon-containing polyurethane. An individual screen 7 shunts currents from electrification arising from mechanical stresses on cable 1. In contrast to metal screens, a conductive plastic screen 7 reduces the weight of cable 1 and metal consumption, increases flexibility, and reduces the minimum bending radius of the cable. Metal screens are made on top of the insulation of the conductor, usually in the form of a spiral tape winding or in the form of a woven mesh of non-ferrous metals (for example, tinned copper). The use of conductive plastic eliminates the need for non-ferrous metals, thereby reducing the metal consumption of the cable. Having a comparable thickness, the weight of the plastic screen is also less than metal, which reduces the total weight of the cable. A plastic screen made in the form of a tube has less bending stiffness than spiral and wicker screens made of metal, which provides increased flexibility of the cable as a whole and, accordingly, the ability of the cable to bend without damage with a smaller radius, i.e. the minimum allowable bending radius of the cable is reduced.

At the time of defibrillator discharge, different electrodes located at different points in the patient's body may have different potentials, which in the absence of protective elements creates an electric current through the cable conductors and through the recording device (recorder). And since the voltage and current strength of the defibrillator discharge are large, the discharge current can lead to the failure of the recording device. Therefore, overvoltage protection elements 8 can be introduced, for example, against a defibrillator discharge, each of which is electrically located between the corresponding conductor 4 and the common shield 6 or between the corresponding conductor 4 and its individual shield 7. As overvoltage protection elements 8 can be applied varistors, suppressors, arresters, zener diodes, etc. The connection of the coaxial conductors 4 through the protection elements 8 with a common screen 6 or with individual screens 7 protects the recorder from discharges of the defibrillator as follows. When a defibrillator is discharged, the current path between electrodes with different potentials passes from one electrode through the protection element 8 to the screen 6 of cable 1, then a limited segment of the screen 6 passes to the other electrode and closes to another electrode through another protection element 8, while the discharge current path passes within the cable only and does not pass through the recording device. High voltage also does not enter the input of the recording device. There is an increase in the service life of the recording device, as when a defibrillator is discharged, the recorder connected to it is not exposed to high voltage, which can lead to its failure.

The inventive cable may contain at least one digital signal channel 9 (Fig. 4) connected to the connector 5 for data transmission, which allows you to connect to cable 1 at least one external digital unit (not shown) or an integrated digital unit 10 (Fig. 5) connected to the digital signal channel 9. This improves the functionality of cable 1, since the external digital unit (not shown) and the integrated digital unit 10 are a source of digital signal and can be used as Motion sensor / position sensor, myographic, okulografichesky, pnevmografichesky sensor storage unit. In this case, the built-in digital unit 10 can be located in the connector 5, in the contact housing 2, separately on the conductor connected to the cable 1. Moreover, several digital units can be connected to one digital signal channel 9. The presence of sensors makes it possible to increase the accuracy of diagnostics by adding additional information parameters for assessing the state of a biological object. And the storage device can further improve the operational properties of the cable, since the storage device can contain an individual cable number 1, which allows the recording device to automatically place this number in the resulting record of monitoring results. When processing the recording, the presence of an individual number will allow you to judge the quality of the cable 1, determine the need for repair or replacement. Also, the storage unit may contain information about the number of monitoring cycles that were performed by this cable 1. This number is automatically modified by the registrar with each subsequent cycle. The number of cycles allows you to assess the condition of cable 1 and the degree of its wear, and also to make a forecast of the remaining resource of its work. Since the wear of cable 1 and, accordingly, the deterioration of signal quality occurs gradually, this process may not always be obvious to the doctor. The forecast of cable resource 1 by the number of settings allows you to avoid situations of critical cable failure during monitoring and, thereby, the loss of a long (daily, multi-day) recording. The presence of such information in the storage unit makes it possible to automatically transfer it to the resulting monitorogram and, subsequently, automatically process this data in information systems.

The inventive cable is used as follows.

Electrodes for biophysiological signals are placed on the patient’s body. These can be ECG electrodes, rheographic electrodes, holders of a motion / body position sensor, temperature sensor, etc. The arrangement of contacts 2 can be different depending on the purpose of the examination (monitoring), as a rule, the arrangement is determined by the applied medical technique. Placed electrodes through contacts 2 are connected to each other by cable 1, cable 1 is connected to the input of the recorder through connectors or through connector 5, thereby the electrodes and sensors placed on the body are electrically connected to the recorder. After the start of registration, the patient can remain in a medical institution or conduct normal life activities in normal living conditions for a given monitoring period (from several hours to several days). At the end of monitoring, the electrodes and sensors are removed from the patient's body. The information accumulated during monitoring is transferred to the information system for further processing in order to obtain diagnostically significant signs.

Claims (5)

1. A device for transmitting biophysiological signals containing a cable and a plurality of contacts connected to it, the cable including a sheath, inside which there are many conductors, and on its outer side at a distance from each other there are many contacts made with the possibility of placement on the surface of the body biological object, each contact is electrically connected to the corresponding conductor, characterized in that a common screen is inserted, placed between the shell and the conductors and located along the entire her length of the conductors. 2. The device according to claim 1, characterized in that each conductor is placed in an individual screen. 3. The device according to p. 2, characterized in that the individual screens are made of semiconductor material. 4. The device according to claim 1, characterized in that overvoltage protection elements are introduced, each of which is electrically located between the corresponding conductor and the common screen. 5. The device according to claim 2, characterized in that overvoltage protection elements are introduced, each of which is electrically located between the corresponding conductor and its individual screen.

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